Optimization Research And Application Of Flue Gas Desulfurization Technology To The 2 Mt/a FCC Unit At Chambroad Petrochemical

With the rapid development of industrial economy,people's living standard is improving and people's awareness of environmental protection becoming more and more intense.The latest"Environmental Protection Law"put forward more stringent requirements clearly on the environmental protection and environmental assessment standards for enterprises.Therefore,how to carry out clean production is very important to the healthy and sustainable development of enterprises.In recent years,people come to realize the environmental hazards caused by the flue gas of refinery processes,represented by catalytic cracking.According to the statistics,the pollutant discharged from the catalytic cracking unit accounted for about 40%-50%of all pollutants in the medium-sized oil refinery.FCC flue gas contains a large amount of sulfur gas,which has become the main air pollution source of refineries in China.According to the requirement of the"13th five-year plan"for SOx emission reduction in flue gas,it is imperative to carry out desulfurization standard for FCC flue gas.Various enterprises have started to research and apply the desulfurization process of refinery flue gas.In this paper,the flue gas desulphurization technology at home and abroad has been discussed.Combining with the characteristics of catalytic cracking unit,the catalytic flue gas SOX removal process was compared and selected.Considering the technology,energy saving,economy,safety,operation reliability and other factors,to ensure that the flue gas SOx emissions to meet the latest emission standards.The process flow and operation parameters of flue gas desulfurization of 2 million tons/year catalytic cracking unit at Chambroad Petrochemicals were analyzed and optimized.Starting from the actual situation of 2 million tons/year catalytic cracking unit of Chambroad Petrochemicals,sodium alkaline wet washing desulfurization process?VSS?was adopted to remove SO₂ in flue gas.The crystallization of waste water from flue gas desulfurization wastewater was compared and analyzed and the feasibility of sodium sulfate recovery from wastewater by evaporation crystallization was verified by experiments.In view of the serious scaling problem in Venturi scrubber,the Venturi scrubber was simulated and optimized,and a reasonable improvement scheme was put forward to ensure the stable operation of the unit.Combined with the actual operation effect of the device and comparative analysis of operation indicators to determine the key indicators and control range of the device for long period safe and smooth operation,the flue gas temperature is 135-140?,the PH of slurry is from 6.5 to 7.5 and the content of salt of slurry is not more than 18%,the content of suspended solids of slurry is not exceeding 100 mg·L^-1.The amount of sulfur transfer catalyst can be adjusted according to the level of slurry salt and the downstream device operation.